ref: 2f850b4e65c8750b40a4447d11f4b0e0217997a2
dir: /sys/src/cmd/gs/src/turboc.cfg/
-wdup -wret -wstr -w-stu -wsus -wvoi -wzst -waus -wdef -w-eff -w-par -w-pia -w-rch -wrvl -w-amb -w-amp -w-nod -w-stv -wuse -wapt -w-cln -wcpt -wdgn -wrpt -w-sig -w-ucp -N